Dejan Stojimirovic

Kathrin Kirchner, Siniša Nešković, Dejan Stojimirović

For business process modeling, we can choose between graph-oriented and block-oriented languages. Block-oriented languages are more structured and therefore better understandable for domain experts, while graph-oriented languages allow more modeling freedom and technical versatility for process designers. To bridge this gap between understandability and technical versatility, we propose a participative forward engineering approach. It uses our block-oriented CUTA4BPM language to support high level process modeling together with domain experts, while graph-oriented BPMN is used for further detailed process design and automation. To support smooth transition from the high level modeling step to the detailed one, CUTA4BPM process models are automatically transformed to BPMN models using model driven engineering techniques.

Sinisa Neskovic, Dejan Stojimirovic

This paper proposes a functional foundation for model driven engineering that unifies model construction, metamodels, templates, and transformations under a single formalism: the model expression algebra. In this algebra, models are values, model expressions are terms, and evaluation is the interpretation homomorphism from terms to values. Model expressions are composed from four operators: model creation and element creation operators, reference operators for retrieving models and elements, and computation operators that embed functional computations. Metamodels are type schemas that constrain the algebra, and model templates, understood as parameterized model expressions, are formalized as open terms with free variables. Model transformations then arise naturally as model templates whose input parameter is a source model. We prove type preservation under evaluation and type safety of transformation execution. Since models are themselves model elements, the algebra also supports megamodels and weaving models without additional mechanisms. The approach is realized through an embedded domain-specific language (DSL) that demonstrates how a single mainstream language can serve simultaneously as the metamodeling, model construction, and transformation language, with formal guarantees enforced by the language's type system.